Phosphoric acid for industrial use — Determination of sulphate content — Method by reduction and titrimetry
NORM herausgegeben am 1.11.1974
Bezeichnung normen: ISO 2997:1974
Ausgabedatum normen: 1.11.1974
Zahl der Seiten: 3
Gewicht ca.: 9 g (0.02 Pfund)
Land: Internationale technische Norm
Kategorie: Technische Normen ISO
Description / Abstract: Applicable to products having sulphate contents equal to or more than 0.0005 % (m/m). Analysis by reduction of the sulphate to sulphide by a mixture of hydriodic acid and hypophosphorus acid. Absorption of the hydrogen sulphide evolved in a mixture of acetone and sodium hydroxide solution. Titration with a standard volumetric solution of mercury(II) acetate in the presence of dithizone as indicator. Has also been approved by the IUPAC.